It can't get any faster or more simple than this.
Base of Whisper White 8 1/2" x 5 1/2" scored at 4 1/4" (100730)
Rich Razzleberry - 5 1/4" x 4" (115316)
Sweet Taffy DSP (133693)
Lots of Thanks stamp set (w-129687 / c-129690) with Rich Razzleberry Ink (126950)
Add a little Organza Ribbon (114319) and you're done!
Oh, and don' forget to give the envelope flap a little color too with some of that dotty DSP!
Thank you for looking in today. I hope you have a fabulous day!